Top roller arrangement in drafting systems of textile machines



J. F. HERUBEL 3,475,792

TOP ROLLER ARRANGEMENT IN DRAFTING SYSTEMS OF TEXTILE MACHINES Nov. 4, 1969 Filed Nov. 5, 1967 'INVENTOR B JEHN FREDERIO HERUBEL United States Patent int. or. twin /50, 5/74 U.S. Cl. 19-267 7 Claims ABSTRACT OF THE DISCLOSURE A top roller arrangement in drafting systems of textile machines includes three elbowed levers. The first lever is pivotally mounted, at an intermediate point, on a stationary support, and is adapted to carry the top roller at one end thereof. The opposite end of the first lever is pivotally connected to a second lever having an operating member at one end and its other end pivotally connected to one end of a third lever. The other end of the third lever is subjected to the action of biasing means bearing against the stationary support. The assembly constitutes a toggle mechanism serving to bring the top roller, relative to the feed roller, into three stable positions. In the first position, the top roller is withdrawn from the feed roller, in the second position, the top roller is applied to the feed roller under a relatively low pressure and, in the third position, the top roller is applied to the feed roller under a relatively high pressure.

This invention relates to textile machines and more specifically to a device for mounting pressing rollers or top-rollers which cooperate with feed-rollers and more especially with feed-rollers employed in drafting systems of spinning machines. By means of said device, the toprollers can be positively applied against the feed-rollers under a given pressure while permitting the possibility of lifting said rollers entirely from their work position by means of a simple movement of small amplitude which entails no effort.

It is known that the pressure exerted by the top-rollers on the feed-rollers, although of a relatively low order, must be constant from one sliver to the next in order to permit a uniform control of the slivers throughout the spinning machine. In addition, it must be possible, in the first place, to adjust said pressure by means of a simple and rapid manual operation and, in the second place, to lift the top-roller to a sufficient extent to pass the sliver into the feed device.

A number of different devices have already been proposed for the purpose of mounting the top-rollers and especially for the purpose of improving the free pressures which are commonly employed in the feed-rollers of spinning machines.

The known devices referred-to have provided only a partial solution to the problem of application of pressure to the rollers. Such devices frequently make use of linkrods or levers actuated by balance weights or springs.

Additionally, many units are of substantial size and have an additional disadvantage in that they cannot lift the top-roller to a suflicient extent to facilitate access to the feed unis.

Furthermore, in some known devices, the work position and the raised position of the top-roller do not correspond to well-defined locking position, so that the roll can inadvertently be set in intermediate positions.

There is also known a drafting system (British Patent No. 885,591) comprising a shaft on which are pivotally mounted a first elbowed lever, which carries the toproller as well as a blade spring, and a second lever, which carries a handle as well as a roller which forms a stop. A third lever is rigidly fixed to said shaft and adapted to carry the articulation of a fourth lever having two arms, one arm being adapted to cooperate with said stop roller while the other arm is intended to exert a pressure on said blade spring. The assembly is designed so as to take up three positions, namely a stable position, in which the top-roller is moved away from the drawing roll, a second floating position, in which the top-roller rests directly on the drawing roll, and a third stable position, in which the top-roller is moved away from the drawing roll.

The known mechanism referred-to about is subject to a certain number of drawbacks, and among these can be mentioned the following: in the third position mentioned above, the top-roller is moved away from the drawing roll only to a small distance and manipulations are consequently difficult to perform. Since the blade spring is incorporated in the system of levers, the available space provided for this latter is small, with the result that the pressure with which the top-roller is applied against the drawing roll can only be of a low order. Furthermore, both hands are required in order to actuate the device.

The device in accordance with the invention is intended to overcome the disadvantages noted above and to permit the top-roller to take up three stable positions. In one position, the top-roller is separated from the feed-roller. In the two other positions, the top-roller is applied against the feed-roller under pressures which are respectively low and high. The device according to the invention is characterized in that it comprises three elbowed levers. The first lever is pivotally mounted at an intermediate point on a stationary support and adapted to carry a top-roller at one end thereof while the other end is fitted with a pivot-pin for the second elbowed lever. The second lever is preferably adapted to carry an operating member at one end thereof while the other end is fitted with a pivot-pin for one end of the third elbowed lever. The other end of said third lever is subjected to the action of an elastic member or the like whose opposite bearing point is located on said stationary support. The complete assembly is so designed as to constitute a toggle mechanism which serves to bring the top-roller, relatively to the feed-roller, into three stable positions corresponding respectively to the withdrawal of the first roller from the second roller, to the application of the first roller against the second roller under low pressure and to the application of the first roller against the second roller under high pressure.

Among other features, the above device offers the following main advantages: it can be actuated with only one hand. In the position of withdrawal of the top-roller this latter is moved to a substantial distance away from the feed-roller, thereby facilitating manual operations which are performed in this position. The device makes it possible to produce directly two different pressures of application of the top-roller having predetermined values which are variable and reproducible. By virtue of the arrangement of the elastic member between the third elbowed lever and a fixed point located outside the set of levers, a large space is thus made available for said elastic member, thereby making it possible to endow said elastic member with any requisite force and even to replace it if necessary by a hydraulic device, pneumatic de vice or the like.

In accordance with another feature of this invention, the second elbowed lever has an embracing profile, with the result that the first and third elbowed levers are capable of fitting to a partial extent within the second elbowed lever.

In accordance with another feature of the invention, the first position of the top-roller (withdrawal of the feed roller) is determined by applying one arm of the third elbowed lever against one arm of the first elbowed lever, the second position (application under low pressure) is determined by applying the end of the third elbowed lever against one arm of the first elbowed lever, and the third position (application under high pressure) is determined by applying one arm of the first elbowed lever against one arm of the second elbowed lever.

In accordance with yet another feature of the invention, the elastic member is constituted by a helical compression spring which is preferably endowed with adjustable tension.

In accordance with still another feature of the invention, the top-roller is mounted on the first elbowed lever in a readily removable manner.

Other properties and advantages of the invention will become apparent from the following description, reference being made to the accompanying drawings, in which:

FIG. 1 shows, diagrammatically and partly in crosssection, a device in accordance with the invention in the position of withdrawal of the top-roller from the feedroller.

FIG. 2 shows, in a similar manner, the application of the top-roller against the feed-roller under low pressure.

FIG. 3 shows, in a similar manner, the application of the top-roller against the feed-roller under high pressure.

FIG. 4 is a view in partial cross-section taken along the line IV-IV of FIG. 3.

FIG. 5 is a view in partial cross-section taken along the line V-V of FIG. 3.

In the embodiment which is illustrated, the reference numeral 1 designates the stationarily mounted feed-roller and 2 designated a top-roller. The said top-roller is constructed in two parts (as shown in FIG. 4) which are joined to each other by means of a shaft 3 pivotally mounted in a first elbowed, or top-roller carrying, lever 4 comprising arms 4a and 4b. The arm 4a is provided with a recess 5 having a rounded edge 5a for the purpose of receiving the shaft 3 which is retained in the said recess by means of a blade spring 6.

For a reason which will appear later, the cross-section of the arm 4:: is thicker than that of the arm 4b.

The lever 4 is pivotally mounted by means of a pin 7 in the forked end 8 of a stationary but adjustable support 9.

The end of the arm 4b of the first elbowed lever is fitted with a pivot-pin 10 for a second elbowed or operating lever 11 the cross-section of which has having an embracing shape, for example a U profile, as is apparent from FIG. 4. The arm 11a of the elbowed lever 11 is provided at its extremity with an operating knob 12 while the end of the other arm 11b is fitted with a pivot-pin 13 for a third elbowed or connecting lever 14.

The end 15 of said lever 14 which is remote from the pivot-pin 13 is applied against the base of a tubular casing 16 which is open at the end opposite to said base and adapted to slide within a bore 17 which is formed in the support 9. Said casing 16 contains a helical compression spring 18, one end of which is applied against the base of the casing while the other end is applied against a threaded end-cap 19 which is screwed into an internally-threaded portion of the bore 17.

The support 9 is carried by a shaft 20 on which it is fixed in the desired position by means of a clamping screw 21.

As noted in the drawings, there are three reference planes for facilitating an understanding of the invention. The first reference plane is indicated at MM in FIGS. 1, 2 and 3, and is a plane joining the pointed end 15 of connecting lever 14 and the pivot axis 7 of the top-roller carrying arm 4. The second plane is indicated at NN in FIG. 1, and joins the axis of feed roller 1 and the axis 3' of top roller 2. The third plane is indicated at P--P in FIGS. 2 and 3, and joins the pointed end 15 of connecting lever 14 to the axis of pin 10 which represents the pivotal interconnection of operating lever arm 11b and the arm 4b of top-roller carrying lever 4.

The above device operates as follows:

FIG. 1 shows the position of the complete assembly in which the top-roller z is separated from the feed-roller 1. In this position, the arm 14a of the third elbowed lever 14 is applied against the arm 4b of the first elbowed lever under the pressure of the spring 18 which is exerted on the end 15 of the elbowed lever 14. The portions of arms 14a and 4b which engage each other will be termed cw operating abutment means or surfaces.

It should be noted that this position of the assembly is a stable position. Furthermore, the top-roller 2 is moved to a substantial distance from the feed-roller 1, thereby facilitating manual operations to be carried out in this position.

In order to apply the top-roller 2 against the feedroller 1 under low pressure, the components must be brought into the position shown in FIG. 2. To this end, the operating knob 12 is actuated so as to cause the lever 11 to pivot about the pin 7 in the direction of the arrow 1 (as shown in FIG. 1), thereby producing the pivotal motion of the elbowed lever 4 the arm 4b of which is maintained within arm 11b of lever 11 under the action of the spring 18 because the pivoted end of connecting lever 14 fixedly located in arm 11b is engaged against arm 4b. The engaged elements thus constitute what will be termed first cooperating abutment means or surface for levers 4 and 11. During this displacement, both levers remain under the control of the elbowed lever 14 which performs a pivotal movement about the pin 13. As and when this movement takes place, the spring 18 is compressed to a progressively greater extent under the action of the lever 14 on the sliding casing 16 until a position of maximum tension is reached when pin 7, pin 13 and end portion 15 are aligned, whereupon the spring 18 tends to expand once again. This movement of expansion is limited by the abutment of the end of the lever 14a against the arm 4b of the first elbowed lever as well as by the application of the top-roller 2 against the feedroller 1.

It should be noted that the transition from the position of FIG. 1 to the position of FIG. 2 entails only a minimum effort in view of the fact that the lever-arm 11a is longer than the lever-arm 11b.

In order to change over from the position of application of the top-roller under low pressure (as shown in FIG. 2) to the position in which said roller is applied with higher pressure, the components must accordingly be brought into the position of FIG. 3 by causing the lever 11 to pivot again in the direction of the arrow f (as shown in FIG. 1). As this movement takes place, the spring 18 is compressed still further and, after having exceeded a maximum value of tension when pin 10, pin 13 and end portion 15 are aligned, said spring expands once again until the edges of the U-shaped profile of the elbowed lever 11 are applied against the arm 40 of the first elbowed lever 4, which is possible in view of the fact that said arm 4a of the first elbowed lever has a thicker cross-section than the arm 4b which is intended to penetrate within the profile of the lever 11. The portions of arms 11a and 4a which engag each other will be termed second cooperating abutment means or surfaces.

This position is also a stable position and corresponds to an application pressure which is higher than that which is reached in the position of FIG. 2 by reason of the fact that the spring 18 is more highly compressed than in the position of FIG. 2, because the distance of pin 13 to the plane joining pin and end portion is shorter in the position of FIG. 3 than in the position of FIG. 2. Furthermore the leverage B is much greater than A.

The application pressure can be adjusted by screwing or unscrewing the threaded end-cap 19. It should be noted in addition that the top-roller 2 can be readily removed by withdrawing its shaft 3 from the recess 5 in opposition to the blade spring 6 or, if necessary, by removing the stop in the case of a rigid attachment.

It is apparent from the foregoing that the above device has many advantages over comparable mechanisms of the prior art, and in particular the following:

(1) In the position of withdrawal, the top-roller is moved to a substantial distance from the feed-roller, thereby facilitating manual operations performed in this position.

(2) The top-roller can readily be removed.

(3) The top-roller can be moved into two positions corresponding to different application pressures.

(4) The three positions of the top-roller are stable, with the result that they can be reproduced with precision.

(5) The device is of very small size and is extremely simple to construct, one reason for this being the fact that all the stops are constituted directly by the levers of the device.

(6) Manipulation is easy and calls for only a small effort, even in the case of a relatively high pressure.

(7) Adjusting the application pressure is easy by reason of the fact that the pressure-adjusting member is readily accessible.

(8) The different components are arranged and mounted in order not to produce a torque which tends to cause the device to rotate about its support.

It is to be understood that the form of execution described hereinabove and illustrated in the accompanying drawings is given solely by way of nonlimitative example. It is therefore apparent that the shape, nature arrangement and assembly of the component parts of the device can be modified in any suitable manner without thereby departing from the scope or the spirit of the invention. Thus, the elbowed levers can have shapes other than those which are illustrated. In addition, the second elbowed lever need have only a partially embracing profile, thereby making it possible to construct the first lever with a constant cross-section.

What I claim is:

1. For a textile machine having a feed roller, a device comprising, in combination, a stationary support; said feed roller being rotatable on an axis which is in a stationary location with respect to said support; a toproller cooperable with said feed roller; a two-arm toproller carrying lever fulcrummed on said support on an axis parallel with that of said feed roller; means mounting said top-roller rotatably in one arm of said top-roller carrying lever for movement toward and away from said feed roller as said top-roller carrying lever is pivoted on its axis; an operating lever pivotally connected to the end of the other arm of said top-roller carrying lever; a connecting lever having one end pivotally connected to a free end of said operating lever; a restoring member recipro'cably mounted on said support for rectilinear movement in a direction substantially parallel to the plane containing the axes of said feed roller and said top-roller, and at right angles to said axes; means resiliently biasing said restoring member toward said other arm of said top-roller carrying lever, said restoring member constantly engaging the other end of said connecting lever; said top-roller carrying lever and said operating lever having first and second cooperating abutment surfaces limiting the amplitude of pivoting movement of said operating lever relative to said top-roller carrying lever in both directions; said top-roller carrying lever and said connecting lever having cooperating abutment surfaces; said operating lever having a first position in which said cooperating abutment surfaces of said top roller carrying lever and said connecting lever are engaged, while the pivotal connection of said connecting lever to said operating lever is located on the same side of a second plane, which includes the pivotal axis of said top-roller carrying lever and said other end of said connecting lever, as is said feed roller, whereby said top-roller is positively maintained spaced from said feed roller; said operating lever having a second position in which the pivotal interconnection of said connecting lever and said operating lever is located on the opposite side of said second plane and at a relatively small spacing therefrom, the pivotal interconnection of said connecting lever and said operating lever being also positioned on the same side, of a third plane, which includes said other end of said connecting lever and the pivotal interconnection of said operating lever and said top-roller carrying lever, as is the pivotal axis of said top-roller carrying lever, whereby said first cooperating abutment surfaces are in engagement and said top-roller is applied against said feed roller under a relatively low pressure; said operating lever having a third position in which the pivotal connection of said operating lever and said connecting lever is located on one side of said third plane while said one arm of said top-roller carrying lever and the pivoting axis of said top-roller carrying lever are located on the opposite side of said third plane, whereby said second cooperating abutment surfaces of said top-roller carrying lever and said operating lever are engaged and the pivotal interconnection of said connecting lever and said operating lever is positioned at a relatively large spacing from said second plane, whereby said top-roller is applied against said feed roller with a relatively high pressure.

2. The device of claim 1, wherein said operating lever is a two-arm lever pivotally connected, intermediate its ends, to the end of said other arm of said top-roller carrying lever; said operating lever including a first arm having its end pivotally interconnected to a pivot end of said connecting lever and extending at an angle to a second arm of said operating lever; said second arm of said operating lever having a U-shaped cross section including two flanges embracing said other arm of said top-roller carrying lever; the lateral thickness of said one arm of said top-roller carrying lever being at least equal to the external lateral dimension of said U-shaped cross section; the edges of said flanges and the facing portions of said one arm of said top-roller carrying lever constituting said second cooperating abutment surfaces.

3. The device of claim 2, wherein the facing portions of said connecting lever and of said other arm of said top-roller carrying lever constitute said cooperating abutment surfaces related to said connecting lever and said other arm.

4. The device of claim 2, wherein the end of said operating lever pivotally connected to the pivot end of said connecting lever is in the form of a clevis embracing the pivoted end of said connecting lever; said pivoted end of said connecting lever and the facing portion of said other arm of said top-roller carrying lever constituting said cooperating abutment surfaces of said top roller carrying lever and said connecting lever.

5. The device of claim 1, wherein said restoring member is a piston reciprocable in a bore of said support;

said biasing means comprising a coil spring mounted in said support and engaged with said piston.

6. The device of claim 5, wherein the distance of the pivotal interconnection of said operating lever and said connecting lever from said third plane is less, in said third position of said operating lever, than in said second position of said operating lever; whereby said coil spring is compressed more strongly, in said third position of said operating lever, for exerting relatively high pressure of said top-roller upon said feed roller.

7. The device of claim 1, including means removably mounting said top-roller in said top-roller carrying lever.

References Cited FOREIGN PATENTS l/ 1962 Italy. 1/1962 Italy.

DORSEY NEWTON, Primary Examiner 

